1. Field of the Invention
This invention relates to a spatial filter, and more particularly, to a spatial filter adequate for implementation in compact optical devices, such as personal health-monitoring devices for distributed healthcare and point-of-care consumer health monitoring devices and to manufacture methods therefor.
2. Description of the Related Art
Micro or sub-millimeter scale pinholes are typically used as spatial filters in precision optical scientific instruments such as interferometers, alignment and inspection instrumentation to perform such functions such as cleaning up laser beam spatial profiles or collimating a finite sized light source in a desired direction. They typically require minimally 3 degrees of freedom with micro-scale resolution and a skilled technician or engineer to align. Such existing spatial filters do not lend itself well for an optically based consumer electronics device where fast volume production is generally necessary.
In light of the above and in view of a general trend for portable and personal monitoring of biochemical substances in the users, there exists a need for an optical filter system and method for making it that are suitable for implementation in cost-efficient and robust optical devices, such as portable self-monitoring devices for distributed diagnostics and personal or home healthcare.